In logging-while-drilling and measurement-while-drilling systems it is advantageous to position one or more sensors as close to the drill bit as possible. The data that is obtained by the sensors is transferred to a subsurface telemetry unit and then transmitted to a surface telemetry unit. Information from the surface may be transmitted to the subsurface telemetry system to the sensors or to control the direction of drilling with steerable systems and the like. Positioning sensors proximate to the drill bit provides data relative to the position of the drill bit and provides greater control of operations to the driller.
In some drilling operations, such as in directional drilling situations, a mud motor is utilized to drive the drill bit. The mud motor converts the flow of the drilling fluid into a rotation of the drill bit and other components positioned below the mud motor. The rotational operation of the mud motor presents an obstacle to providing electrical wiring to sensors or other electronics positioned below the mud motor. Thus, in drilling operations in which real time positional and wellbore data proximate to the drill bit is at a premium, the positioning of sensors near the bit is prohibitive.